Illuminating dial



1,642,676 p 1927' v A. H. GREBE ILLUMI NATING DIAL Filed May 28, 1925 2 Sheets-Sheet 1 1,642,676 p 3 A. H. GREBE 1 ILLUMINATING DIAL Filed May 28, 1925 2 Sheets-Sheet 2 70 90 ml]!!!IIHHIHIIIIIHIIIIIIIII]IIIHIIIIHIIllI 1 H mid 4w,

g max/44 QYENIL Patented Sept. 20, 1927.

UNITED STATES,

ALFRED HENRY GREBE, or HOLLIS, NEW YORK.

ILLUMINATING DIAL.

Application filed Kay 28, 1925. Serial N0. 33,424.

the scales to determine proper or necessary adjustment of the control members.

For convenience of illustration, the present embodiment of the invention is specially designed for application to a radio receiver, the control dials of which, must, ordinarily, be adjusted to a nicety, to tune the set to resonance at various frequencies.

In the average household, the radio receiver is found placed at such distance from 7 either natural or artificial light, that it is impossible to readily and conveniently read the scales of the control dials and, as a result,-the average user works in semi-darkness and experiences considerable difiiculty in tuning in.

In order to remedy this trouble, the present invention is designed to illuminate the control dial scales by a glow, reflected from concealed sources of artificial light. Shieldi ing of the sources of light avoids an objectionable glare from the set and permits the light to be directed and concentrated on points of. the dial scales where the readings are taken.

Another ieature of; the invention consists in utilizing the dial scale lam s as tell-tale lights for the vacuum tubes 0 the receiver. This is accomplished by connecting such lampsin circuit with the tubes, so as to be simultaneously controlled by the filament rheostat. I

The accompanying drawings will serve to illustrate a construction and arrangement suitable for carrying my invention into effect. e

In the drawings- Fig. 1 is a view in elevation, showing a portion of the front of the panel of a radio receiver;

Fig. 2 is a detail view, on an enlarged scale, showing one of the dial lamps;

Fig. 3 is a cross-sectional view taken on the line 3-3, of Fig. 1; I

Fig. 4 is a similar view, on an enlarged scale showing additional details;

Fig. 5 is a view from the rear of Fi 4;

Fig. 6 illustrates a modification, an

Fig. '7 is a circuit diagram showing the dial scale lamps connected in circuit with the vacuum tubes of the receiverand under the control of the tube filament rheostet.

Referring now to the drawings, 1 indicates the panel of a Synchrophase receiver, a type of radio set in which the control dials 2, 2, 2, of the variable tuning elements (not shown) are arranged to present their scaled peripheral faces through slots 3, 3, 3, cut in the panel.

Ornamental sheet metal escutcheons 4, suitably shaped and slotted to encircle and conform to the projecting portions of the control dials, and which, ordinarily, serve only to give a finish to the face of the panel, are here utilized as reflectors for directing light from lamps 5, downward through narrow arc-shaped openings 6, upon the scaled faces 7, of the dials.

The lamps shown are in the form of small electric bulbs, removably mounted, in the usual manner, in sockets 8, hinged at 9, to the panel and yieldingly held in position by springs 10 and stops 11, the arrangement being such as to permit the hinged lamps to be swungaround and the bulbs renewed in case of burn-outs. A reflector 12, may be employed, if desired, to concentrate the rays of light at the center of the dial face, where the reading is ordinarily taken and .for guidance in adjusting the dials with reference to a fixed point, a small opening 13, is formed at the center of each ascilitcheon adjacent to the scaled face of the The dial lamps 5 are shown connected in series multiple relation, in circuit with the vacuum tubes 14 of the receiver and, as arranged, simultaneous control is obtained by means of the usual rheostat 15.

The manner of connecting'the tubes and lamps in circuit may be varied,'if desired, but I "prefer the arrangement shown, as the simultaneous control by the filament rheostat causes the dial lam s to act as tell-tales for the tubes, enabling the o rator to jud e the brilliance of the tube filaments by the intensity of the glow on the dial scales.

In Fig. 6, a modification is shown ,of adapting the lighting system above described to radio receivers or other apparatus or instruments in ,which dials are mounted and arranged in planes arallel with the anel.

The operation an advantages of the invention will be apparent from the foregoing 1. In an apparatus. for illuminatin g the control dials of a radio receiver, a panel projecting control dia s, lamps mounted on,

the rear of said panel directly opposite said reflectors and spring means for yielding'ly securing said lamps in a position adjacent said control dials and behind said reflectors for illuminating said control dials. 2. In an, apparatus for illuminating the control dials of a radio receiver a panel structure apertured for the projection of a lurality of control dials therethrough, re ectors secured to the front of said panel structure for substantially closing the apertured portion of said panel structure and around said control dials and lamp devices yieldingly secured o the rear of said panel structure in positions whereby said lamps extend through the apertured 'ortions of said panel structure immediatel hind said reflectors and over said contro dials for illuminating the peripheral edge of said control dials! 3. In an apparatus for illuminating the control dials oi: a radio receiver, a panel structure apertured for the projection of a lurality of control dials therethrough, a re ector secured to the frontof said panel structure in positions over the apertured .tured' portions of said control dials .apertured panel structure, a control dial proportions ofsaid anel structure and servin as a frame for t e ripheral ed e of sai control dials, lam evices hinged y mounted'on the rear 0 said anel structure and spring pressed to a position within the aperv anel structure immediately behindsaid re control dials for illuminating the peripheral edge of said control dials.

, 4. In an apparatus for illuminating the 0 radio receiver apparatus, an

jecting through apertured portions of said anel structure, a'reflector secured to the rout of said dpanel structure and forming a frame aroun the projecting edge of said control dials, hingedly mounted bracket members secured to the rear of said panel behind said reflectors, a lamp carried by each of said hingedly mounted brackets, spring means for urging said lamps to a position ectors and over said within the apertured portions of said panel 1 structure over said control dials and behind.

said reflectors and limiting sto s on said bracket members arranged to a ut against the upper apertured portions of said panel structure for fixing the position of said lamps behind said reflectors.

ALFRED (mam. 

